Isolotto (small island) is the first prototype of an artificial island able to sustain marine life in the Mediterranean Sea. It is realized using only biodegradable materials like cork, gypsum, and natural glue (no screws or other chemical substances have been used). The floating island will break down naturally and all the elements will decompose and transform into other components like nutrients, bacteria, and other mineral forms without polluting the environment.
Photo: Angelo Renna
We have tested how the bottom topography of the island could help to grow underwater plants. The geometric variations provide upside-down hills with peaks and valleys that serve as habitats for different types of invertebrates, mosses, and plants. Above water, we created a small protected concave area to locate a multilayered substrate planted with bushes and plants (in particular small trees and plants able to resist strong wind).
Angelo Renna
It is composed of an inner structure entirely assembled using cork layers of 1 cm. This structure is able to guarantee enough resistance to support a proper package of soil for plants and vegetation, and, at the same time, it is an extremely light material that allows the island to float.
The external layer of the island plays a fundamental role; in fact, this stratum allows plants, vegetation, and microorganisms to “occupy” the island and create new habitats. It is realized using gypsum: a natural and non-toxic material present in the form of rock and grinding it to a fine powder composed of calcium and sulfate.
The powder when mixed with water becomes a paste. The paste can then be molded or troweled, and it will harden in an endothermic (heat-producing) reaction. In the tests, Angelo Renna and Apurva Baldawa ran the gypsum was able to degrade much slower than the clay and the terracotta preserving the inner part a bit longer and stretching the period of the degradation.
The island has been released into the water on July 5 of this year (2023) in the Mediterranean Sea in the Tuscany Archipelago and in the coming months will start decomposing and disappear in the water. Soon it will be launched a crowdfunding to realize a bigger version of the island extending the research to other topics like marine pollution and marine ecosystems.
